1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * fixed.c 4 * 5 * Copyright 2008 Wolfson Microelectronics PLC. 6 * 7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 * 9 * Copyright (c) 2009 Nokia Corporation 10 * Roger Quadros <ext-roger.quadros@nokia.com> 11 * 12 * This is useful for systems with mixed controllable and 13 * non-controllable regulators, as well as for allowing testing on 14 * systems with no controllable regulators. 15 */ 16 17 #include <linux/err.h> 18 #include <linux/mutex.h> 19 #include <linux/module.h> 20 #include <linux/platform_device.h> 21 #include <linux/pm_domain.h> 22 #include <linux/pm_opp.h> 23 #include <linux/regulator/driver.h> 24 #include <linux/regulator/fixed.h> 25 #include <linux/gpio/consumer.h> 26 #include <linux/slab.h> 27 #include <linux/of.h> 28 #include <linux/of_device.h> 29 #include <linux/regulator/of_regulator.h> 30 #include <linux/regulator/machine.h> 31 #include <linux/clk.h> 32 33 34 struct fixed_voltage_data { 35 struct regulator_desc desc; 36 struct regulator_dev *dev; 37 38 struct clk *enable_clock; 39 unsigned int enable_counter; 40 int performance_state; 41 }; 42 43 struct fixed_dev_type { 44 bool has_enable_clock; 45 bool has_performance_state; 46 }; 47 48 static int reg_clock_enable(struct regulator_dev *rdev) 49 { 50 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 51 int ret = 0; 52 53 ret = clk_prepare_enable(priv->enable_clock); 54 if (ret) 55 return ret; 56 57 priv->enable_counter++; 58 59 return ret; 60 } 61 62 static int reg_clock_disable(struct regulator_dev *rdev) 63 { 64 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 65 66 clk_disable_unprepare(priv->enable_clock); 67 priv->enable_counter--; 68 69 return 0; 70 } 71 72 static int reg_domain_enable(struct regulator_dev *rdev) 73 { 74 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 75 struct device *dev = rdev->dev.parent; 76 int ret; 77 78 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state); 79 if (ret) 80 return ret; 81 82 priv->enable_counter++; 83 84 return ret; 85 } 86 87 static int reg_domain_disable(struct regulator_dev *rdev) 88 { 89 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 90 struct device *dev = rdev->dev.parent; 91 int ret; 92 93 ret = dev_pm_genpd_set_performance_state(dev, 0); 94 if (ret) 95 return ret; 96 97 priv->enable_counter--; 98 99 return 0; 100 } 101 102 static int reg_is_enabled(struct regulator_dev *rdev) 103 { 104 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 105 106 return priv->enable_counter > 0; 107 } 108 109 110 /** 111 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info 112 * @dev: device requesting for fixed_voltage_config 113 * @desc: regulator description 114 * 115 * Populates fixed_voltage_config structure by extracting data from device 116 * tree node, returns a pointer to the populated structure of NULL if memory 117 * alloc fails. 118 */ 119 static struct fixed_voltage_config * 120 of_get_fixed_voltage_config(struct device *dev, 121 const struct regulator_desc *desc) 122 { 123 struct fixed_voltage_config *config; 124 struct device_node *np = dev->of_node; 125 struct regulator_init_data *init_data; 126 127 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), 128 GFP_KERNEL); 129 if (!config) 130 return ERR_PTR(-ENOMEM); 131 132 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc); 133 if (!config->init_data) 134 return ERR_PTR(-EINVAL); 135 136 init_data = config->init_data; 137 init_data->constraints.apply_uV = 0; 138 139 config->supply_name = init_data->constraints.name; 140 if (init_data->constraints.min_uV == init_data->constraints.max_uV) { 141 config->microvolts = init_data->constraints.min_uV; 142 } else { 143 dev_err(dev, 144 "Fixed regulator specified with variable voltages\n"); 145 return ERR_PTR(-EINVAL); 146 } 147 148 if (init_data->constraints.boot_on) 149 config->enabled_at_boot = true; 150 151 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 152 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); 153 154 if (of_property_present(np, "vin-supply")) 155 config->input_supply = "vin"; 156 157 return config; 158 } 159 160 static const struct regulator_ops fixed_voltage_ops = { 161 }; 162 163 static const struct regulator_ops fixed_voltage_clkenabled_ops = { 164 .enable = reg_clock_enable, 165 .disable = reg_clock_disable, 166 .is_enabled = reg_is_enabled, 167 }; 168 169 static const struct regulator_ops fixed_voltage_domain_ops = { 170 .enable = reg_domain_enable, 171 .disable = reg_domain_disable, 172 .is_enabled = reg_is_enabled, 173 }; 174 175 static int reg_fixed_voltage_probe(struct platform_device *pdev) 176 { 177 struct device *dev = &pdev->dev; 178 struct fixed_voltage_config *config; 179 struct fixed_voltage_data *drvdata; 180 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); 181 struct regulator_config cfg = { }; 182 enum gpiod_flags gflags; 183 int ret; 184 185 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), 186 GFP_KERNEL); 187 if (!drvdata) 188 return -ENOMEM; 189 190 if (pdev->dev.of_node) { 191 config = of_get_fixed_voltage_config(&pdev->dev, 192 &drvdata->desc); 193 if (IS_ERR(config)) 194 return PTR_ERR(config); 195 } else { 196 config = dev_get_platdata(&pdev->dev); 197 } 198 199 if (!config) 200 return -ENOMEM; 201 202 drvdata->desc.name = devm_kstrdup(&pdev->dev, 203 config->supply_name, 204 GFP_KERNEL); 205 if (drvdata->desc.name == NULL) { 206 dev_err(&pdev->dev, "Failed to allocate supply name\n"); 207 return -ENOMEM; 208 } 209 drvdata->desc.type = REGULATOR_VOLTAGE; 210 drvdata->desc.owner = THIS_MODULE; 211 212 if (drvtype && drvtype->has_enable_clock) { 213 drvdata->desc.ops = &fixed_voltage_clkenabled_ops; 214 215 drvdata->enable_clock = devm_clk_get(dev, NULL); 216 if (IS_ERR(drvdata->enable_clock)) { 217 dev_err(dev, "Can't get enable-clock from devicetree\n"); 218 return PTR_ERR(drvdata->enable_clock); 219 } 220 } else if (drvtype && drvtype->has_performance_state) { 221 drvdata->desc.ops = &fixed_voltage_domain_ops; 222 223 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0); 224 if (drvdata->performance_state < 0) { 225 dev_err(dev, "Can't get performance state from devicetree\n"); 226 return drvdata->performance_state; 227 } 228 } else { 229 drvdata->desc.ops = &fixed_voltage_ops; 230 } 231 232 drvdata->desc.enable_time = config->startup_delay; 233 drvdata->desc.off_on_delay = config->off_on_delay; 234 235 if (config->input_supply) { 236 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev, 237 config->input_supply, 238 GFP_KERNEL); 239 if (!drvdata->desc.supply_name) 240 return -ENOMEM; 241 } 242 243 if (config->microvolts) 244 drvdata->desc.n_voltages = 1; 245 246 drvdata->desc.fixed_uV = config->microvolts; 247 248 /* 249 * The signal will be inverted by the GPIO core if flagged so in the 250 * descriptor. 251 */ 252 if (config->enabled_at_boot) 253 gflags = GPIOD_OUT_HIGH; 254 else 255 gflags = GPIOD_OUT_LOW; 256 257 /* 258 * Some fixed regulators share the enable line between two 259 * regulators which makes it necessary to get a handle on the 260 * same descriptor for two different consumers. This will get 261 * the GPIO descriptor, but only the first call will initialize 262 * it so any flags such as inversion or open drain will only 263 * be set up by the first caller and assumed identical on the 264 * next caller. 265 * 266 * FIXME: find a better way to deal with this. 267 */ 268 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; 269 270 /* 271 * Do not use devm* here: the regulator core takes over the 272 * lifecycle management of the GPIO descriptor. 273 */ 274 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags); 275 if (IS_ERR(cfg.ena_gpiod)) 276 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod), 277 "can't get GPIO\n"); 278 279 cfg.dev = &pdev->dev; 280 cfg.init_data = config->init_data; 281 cfg.driver_data = drvdata; 282 cfg.of_node = pdev->dev.of_node; 283 284 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc, 285 &cfg); 286 if (IS_ERR(drvdata->dev)) { 287 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev), 288 "Failed to register regulator: %ld\n", 289 PTR_ERR(drvdata->dev)); 290 return ret; 291 } 292 293 platform_set_drvdata(pdev, drvdata); 294 295 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, 296 drvdata->desc.fixed_uV); 297 298 return 0; 299 } 300 301 #if defined(CONFIG_OF) 302 static const struct fixed_dev_type fixed_voltage_data = { 303 .has_enable_clock = false, 304 }; 305 306 static const struct fixed_dev_type fixed_clkenable_data = { 307 .has_enable_clock = true, 308 }; 309 310 static const struct fixed_dev_type fixed_domain_data = { 311 .has_performance_state = true, 312 }; 313 314 static const struct of_device_id fixed_of_match[] = { 315 { 316 .compatible = "regulator-fixed", 317 .data = &fixed_voltage_data, 318 }, 319 { 320 .compatible = "regulator-fixed-clock", 321 .data = &fixed_clkenable_data, 322 }, 323 { 324 .compatible = "regulator-fixed-domain", 325 .data = &fixed_domain_data, 326 }, 327 { 328 }, 329 }; 330 MODULE_DEVICE_TABLE(of, fixed_of_match); 331 #endif 332 333 static struct platform_driver regulator_fixed_voltage_driver = { 334 .probe = reg_fixed_voltage_probe, 335 .driver = { 336 .name = "reg-fixed-voltage", 337 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 338 .of_match_table = of_match_ptr(fixed_of_match), 339 }, 340 }; 341 342 static int __init regulator_fixed_voltage_init(void) 343 { 344 return platform_driver_register(®ulator_fixed_voltage_driver); 345 } 346 subsys_initcall(regulator_fixed_voltage_init); 347 348 static void __exit regulator_fixed_voltage_exit(void) 349 { 350 platform_driver_unregister(®ulator_fixed_voltage_driver); 351 } 352 module_exit(regulator_fixed_voltage_exit); 353 354 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 355 MODULE_DESCRIPTION("Fixed voltage regulator"); 356 MODULE_LICENSE("GPL"); 357 MODULE_ALIAS("platform:reg-fixed-voltage"); 358